android6.0 camera2 录像 MediaRecorder.getsurface 失败

Question

Android版本：6.0，实现功能：录像  代码如下： 
 mMediaRecorder = new MediaRecorder();                                
 mMediaRecorder.setVideoSource(MediaRecorder.VideoSource.SURFACE);    
 mMediaRecorder.setOutputFormat(MediaRecorder.OutputFormat.THREE_GPP);
 mMediaRecorder.setOutputFile("/sdcard/surface.3gp");                 
 mMediaRecorder.setVideoFrameRate(30);                                
 mMediaRecorder.setVideoSize(352, 288);                               
 mMediaRecorder.setVideoEncoder(MediaRecorder.VideoEncoder.H264);     
 try{                                                                 
     mMediaRecorder.prepare();                                        
 }catch(IOException e)                                                
 {                                                                    
                                                                      
 }                                                                    
 Surface recorderSurface = mMediaRecorder.getSurface();  
执行到     最后一行出现错误： E/MediaRecorder: SurfaceMediaSource could not be initialized!
                                                java.lang.IllegalStateException: failed to get surface

Answer 1

mMediaRecorde.setPreviewDisplay(mSurfaceHolder.getSurface)

Answer 2

这个应该是权限问题，动态申请{Manifest.permission.CAMERA,Manifest.permission.WRITE_EXTERNAL_STORAGE,Manifest.permission.READ_EXTERNAL_STORAGE,Manifest.permission.RECORD_AUDIO}这些，并在Manifes中加上  <uses-feature android:name="android.hardware.camera" />
    <uses-feature android:name="android.hardware.camera.autofocus" /> 这2个，